Help for Mercedes S320 /2006

Hello, my German is a bit sloppy because I would like to apologize. I am from Bulgaria and I have a mercedes S 320 CDI – BJ 2006 i and approx. 110 tkm. In december I have a turbo damage at 98 000 km. I was at Mercedes and I waited 30 days for turbo and motor blok to change. On 28.12.2007 the car was vertig, but after 2000 km. was vieder turboshad and vieder 20 days vartezeit. On 23.01.2008 was vertig. Vieder after 7500 km. turbo and motor blok was kaput. now au to steet at Mercedes vieder and I wait. can you help me: Can I change car at mercedes or get money touk or what can I do. Thank you